Vitamin D Deficiency: An Increasing Concern in Peripheral Arterial Disease

Vitamin D Deficiency as a Risk Factor of Tinnitus: An Epidemiological Study

OBJECTIVES

Vitamin D deficiency as a risk factor of tinnitus has not been well known. We tried to evaluate the association between the serum 25-(OH) vitamin D levels and tinnitus among the Korean population to propose the possible role of serum vitamin D in patients with tinnitus.

METHODS

This cross-sectional study investigated the potential risk factors of tinnitus in relation to serum 25(OH)D levels within the Korean population. It encompassed a health interview, nutrition assessment, and a health examination. Data was sourced from the KNHANES V (2010-2012), conducted by the Division of Health and Nutritional Survey under the Korean Centers for Disease Control and Prevention (KCDCP). Participants were chosen from various sampling units categorized by geography, gender, and age group. The selection was facilitated through household registries using a stratified, multistage, clustered probability sampling approach.

RESULTS

Data of 16 408 subjects were collected in this study. There were significant differences in gender, economic status, educational level, and sun exposure duration between the tinnitus and non-tinnitus groups. Serum 25(OH) vitamin D level between hearing loss and normal hearing was also significantly different. The logistic regression models with serum 25(OH) vitamin D quartile and tinnitus as the dependent variable, which were controlled for age, sex, smoking status, BMI, diabetes, hypertension, sun exposure, regular exercise, income, and education, eventually demonstrated that serum vitamin D deficiency and low sun exposure duration significantly increased the risk of tinnitus development.

CONCLUSION

This study demonstrated a significant association between serum vitamin D levels and tinnitus, driven by large epidemiological data. The results of our study provide baseline data for further research to investigate the role of vitamin D in the pathogenesis and management of tinnitus.

An evaluation of the validity of nutrition screening and assessment tools in patients admitted to a vascular surgery unit

Vascular surgery patients are nutritionally vulnerable. Various malnutrition screening and assessment tools are available; however, none has been developed or validated in vascular patients. The present study aimed to: (1) investigate the validity of four commonly administered malnutrition screening tools (Malnutrition Screening Tool (MST), Malnutrition Universal Screening Tool (MUST), Nutrition Risk Screen-2002 (NRS-2002) and the Mini-Nutritional Assessment - Short Form (MNA-SF) and an assessment tool (the Patient-Generated Subjective Global Assessment (PG-SGA)) compared against a comprehensive dietitian's assessment and (2) evaluate the ability of the instruments to predict outcomes. Vascular inpatients were screened using the four malnutrition screening tools and assessed using the PG-SGA. Each was assessed by a dietitian incorporating nutritional biochemistry, anthropometry and changes in dietary intake. Diagnostic accuracy, consistency and predictive ability were determined. A total of 322 (69·3 % male) patients participated, with 75 % having at least one parameter indicating nutritional deficits. No instrument achieved the a priori levels for sensitivity (14·9-52·5 %). Neither tool predicted EuroQoL 5-dimension 5-level score. All tools except the MNA-SF were associated with length of stay (LOS); however, the direction varied with increased risk of malnutrition on the MUST and NRS-2002 being associated with shorter LOS (P=0·029 and 0·045) and the reverse with the MST and PG-SGA (P=0·005 and <0·001). The NRS-2002 was associated with increased risk of complications (P=0·039). The MST, NRS-2002 and PG-SGA were predictive of discharge to an institution (P=0·004, 0·005 and 0·003). The tools studied were unable to identify the high prevalence of undernutrition; hence, vascular disease-specific screening and/or assessment tools are warranted.

Hypovitaminosis D and peripheral arterial disease: emerging link beyond cardiovascular risk factors

Vitamin D has received increasing interest for its beneficial effect on health. Beyond its conventional role in bone metabolism, emerging evidence suggests a possible link between low vitamin D levels and cardiovascular disease (CVD), including peripheral arterial disease (PAD), and cardiovascular risk factors. Vitamin D interacts either directly with the vascular tree or indirectly through its association with cardiovascular risk factors, but the exact mechanism remains controversial. This review outlines the association between hypovitaminosis D and PAD. Both entities are quite prevalent in the general population and, therefore, their potential association might have important clinical implications. Whether vitamin D deficiency represents a novel risk factor for PAD/CVD, and whether vitamin D supplementation would reduce the burden of CVD still remains to be answered. Until then, vitamin D intake is not recommended for PAD/CVD prevention. Outdoor physical activity, coupled with adequate but safe sun exposure, is a healthy lifestyle practice suggested for the prevention of both PAD and hypovitaminosis D.

Gene expression profiling of peripheral blood mononuclear cells in the setting of peripheral arterial disease

BACKGROUND

Peripheral arterial disease (PAD) is a relatively common manifestation of systemic atherosclerosis that leads to progressive narrowing of the lumen of leg arteries. Circulating monocytes are in contact with the arterial wall and can serve as reporters of vascular pathology in the setting of PAD. We performed gene expression analysis of peripheral blood mononuclear cells (PBMC) in patients with PAD and controls without PAD to identify differentially regulated genes.

METHODS

PAD was defined as an ankle brachial index (ABI) ≤0.9 (n = 19) while age and gender matched controls had an ABI > 1.0 (n = 18). Microarray analysis was performed using Affymetrix HG-U133 plus 2.0 gene chips and analyzed using GeneSpring GX 11.0. Gene expression data was normalized using Robust Multichip Analysis (RMA) normalization method, differential expression was defined as a fold change ≥1.5, followed by unpaired Mann-Whitney test (P < 0.05) and correction for multiple testing by Benjamini and Hochberg False Discovery Rate. Meta-analysis of differentially expressed genes was performed using an integrated bioinformatics pipeline with tools for enrichment analysis using Gene Ontology (GO) terms, pathway analysis using Kyoto Encyclopedia of Genes and Genomes (KEGG), molecular event enrichment using Reactome annotations and network analysis using Ingenuity Pathway Analysis suite. Extensive biocuration was also performed to understand the functional context of genes.

RESULTS

We identified 87 genes differentially expressed in the setting of PAD; 40 genes were upregulated and 47 genes were downregulated. We employed an integrated bioinformatics pipeline coupled with literature curation to characterize the functional coherence of differentially regulated genes.

CONCLUSION

Notably, upregulated genes mediate immune response, inflammation, apoptosis, stress response, phosphorylation, hemostasis, platelet activation and platelet aggregation. Downregulated genes included several genes from the zinc finger family that are involved in transcriptional regulation. These results provide insights into molecular mechanisms relevant to the pathophysiology of PAD.

Vitamin D status and peripheral arterial disease: evidence so far

Background

Vitamin D deficiency has recently been implicated as a contributory factor in the development of peripheral arterial disease (PAD).

Methods

A review of the published literature on PAD and vitamin D was undertaken using Medline, PubMed, and Embase, and cross-referenced. All relevant published papers on the subject were reviewed.

Results

Published studies have shown that there is a significant association between vitamin D and PAD. Populations with lower vitamin D levels are more likely to develop PAD in a graded manner. Higher amputation rates are also observed among patients with PAD and lower vitamin D levels. In addition, vitamin D deficiency is significantly associated with increased risk of cardiovascular adverse events. This was also observed in the mouse model where low vitamin D led to the development of atherosclerosis.

Conclusion

This study shows that vitamin D deficiency could be an independent risk factor for the development of PAD and that this risk factor is easily correctable. Further studies should look into the effects of vitamin D supplementation in patients with PAD.